Adjustable drill chuck



L. H. VO LD ADJUSTABLE DRILL CHUCK Nov. 23 1926. 1,607,709

Filed Feb: 4, 1925 WITNESSES INVENTOR I im, H.7r aL Patented Nov. 23,1926.

UNITED STATES LABS H. VOLD, 0F BUTLER, PENNSYLVANIA.

ADJUSTABLE DRILL CHUCK.

Application filed February 4, 1925.

This invention relates to multiple drill presses, and particularly toadjustable drill chucks for use in connection therewith.

Heretofore, in drill presses of this character, it has been frequentlynot only inconvenient to easily, quickly, and accurately adjust theentire number or gang of bits used to the desired relative positionsaxially of the bits but great difficulty has been experienced topositively lock the bits against displacement after the desiredadjustment is made. It is highly desirable to provide a multiple drillpress equipped with means which will enable the operator to easily andquickly bring the tips of all of the bits employed into exact alignment,or other necessary relative disposition required by the work beingoperated upon, which will at the same time assure such setting beingpositively 1naintained when once made, regardless of the simultaneousbodily movement of the entire gang of bits as a unit during repeateduse. It is the object of the invention to provide a constructionpossessing the advantages noted.

It is a special object to provide a construction in which the rotatingdriving spindle for each of the bits includes a tool-holding elementconnected thereto adapted to contact an adjustable abutment carried bythe spindle threadedly mounted axially of the spindle and provided atone end with a con tact face with the side face of the threadscontacting the abutment facing towards the end contact face especiallyinclined and diverging away from the same whereby to increase its areaof contact with the abutment, and preferably of greater area than theopposite side face of the thread.

It is also a special object to provide a construction in which the meansrotatably driving the drill bits includes a rotatable spindle, atool-carrying element and a limiting abutment both threadedly mountedupon a suitable part carried by the spindle, the side face of the threadcontacting the abutment and facing towards the end thereof provided withthe limiting contact face being espe cially inclined whereby the saidsideface diverges radially from the axis of the spindle at a smallerangle than the opposite side face of said thread.

It is another special object to provide a construction in which thethreaded connection between the adjustable abutment and driving spindleis such. as to generate under Serial No. 6,692.

the axial thrust of the tool-carrying ele ment a greater frictionalresistance between the said abutment and the driving spindle to turningmovementupon the spindle than that exerted between the contactingportions of the tool-carrying element and the said abutment.

It is still a further special object to provide a drill chuck having atool-holding element and an adjustable limiting abutment both threadedlymounted upon a driving spindle so constructed or provided with means forreducing the friction between the contacting surfaces of the saidelement and abutment whereby the tendency of the turning movement of thetool-holding element to effect turning movement of the abutment will bereduced to a minimum.

These and other objects of the invention will more fully appear whentaken in conjunction with the following description and the appendedclaims.

In the accompanying drawings forming a part of the application, Fig. 1is a fragmentary perspective view of a portion of a multiple drill pressequipped with the present invention; Fig. 2 a side elevation of one formof the invention, illustrating the rotatable driving spindle and theremaining portions forming the adjustable drill chuck on an enlargedscale; and Fig. 3 a similar view, shown partly in section and partly inelevation, illustrating a modified form of the invention.

In the drawings, 1 represents the frame of a multiple drill providedwith the head 2, and the work table 3, all as common to machines of thissame general character. The

.machine may be equipped with any desired number of chucks, each ofwhich is rotatable and driven by means of a separate driving spindlethrough suitable gearing housed within the head 2 and thesuper-structure of the press. None of these parts, except in so far assubsequently described form a part of the present invention, and havetherefore not been illustrated in greater detail, the showing in Fig. 1being sufficient to those familiar with this art to clearly indicate themethod of mounting the chucks and their coordination with the remainingparts.

In both forms of the invention illustrated, a rotatable drivingspindle tis provided for each of the bits 5, the usual tapered shank 5 of thebits being adapted to be received by a ssrrespondingly shaped. socket atone end fin ot a tool-holding or carryin element desig nated generallyby the reference numeral 6, all as common in the art.

The element 6 is cylindrical in shape and provided with an axialinternally threaded bore extending inwards from its end oppo site thebit-receiving socket which bore threadedly receives the terminalexteriorly threaded portion l of the driving spindle 4.

Also threadedly mounted upon the terminal of the driving spindle and inaxial alignment with the tool-holding element 6 is a cylindricalabutment collar 7.

The portion of the terminal t which cooperates with the abutment collar7, the in terior threads on the collar of course being correspondinglyformer, is equipped with peculiarly shaped threads in which the sidetace 8 thereof facing the end contact taco on the tool-holding elementis especially inclined away from the said contact "face. and divergesradially from the axis of the spindle in the direction of the headthereby increasing the area of the said side face over that or theopposite side taco of the thread. In other words, the side taco S is sosnaped as to diverge radially from the axis of the spindle at a smallerangle than the opposite side tare oi the thread, bot-l1 races of coursefollowing the customary pitch of the thread as a whole.

Although this feature need not be extended to the portions of thethreaded terminal a coacting only with the tool-holding element, forconvenience in manufacture and manipulation the same form of. thread isused throughout the entire terminal portion of the spindle cooperatingwith both the tool-holding element 6 and the abutment collar 7.

To this point oi the description both embodiments of the invention, asillustrated in the drawings, are identically alike and the correspondingparts the-reot have been designated by the same reference numerals.

in the term shown in Fig. 2, the end face 9 of the tool-holding elementadapted to directly abut in intimate contact the contiguous end contactface 10 ot the abutment, and for a purpose to be subsequently describedmore at length these end faces are highly polished. to produce planesmooth surfaces thereby reducing friction therebetween and the tendencyof the one to turn in response to turning iovement of the other. Tofacilitate the manual adjustment, both these members may be knurled overapyn'opriate areas as indicated at 11 and 12.

The modification shown in Fig. 3 differs from that o1 Fig. 2 in that anantrlriction bearing; is interposed between the contiguous end faces ofthe tool-holding element 6 and the abutment collar 7. As illustrated, aball bearing is employed comprising the ball retaining ring 13 havingsuitably spaced apert for receiving the anti-friction balls l Elwhichare adapted to contact and ride upon the end oi? the element 6 and theabutment 7, the diameter of the balls being preferably slightly greaterthan the thickness of their retaining ring, as l v y shown in thedrawings. The intercie position oi this special anti-friction bearing;eliminates substantially all friction between the element (3 and theabutment 7 thereby practically obviating all tendency for the collar toturn upon the spindle due to rotation of the tool-holding element. Dueto this tact, it has been found with this tor-n1 ot' the invention thespecially inclined face 8 on the thread may be dispensed with andordinary terms ot' threads employed instead.

The method of adjusting the gang of bits, preliminarily to the actualdrilling operation, will now be descr'bed. The several tool-holdingelements 6 are rotated ausing them to ride upon their spindles so as tobrin the tips of all oi the bits 5 into exact alignment in which all ofthe tips will lie in the same plane or into any relative positionsaxially of the. spindle, as required by the character of the worl: beingoperated upon. W hen thus positioned the abutment collars 7 are rotatedcausing them to ride towards the tool-holding elements until broughtinto contact therewith, as shown in Fig. 2. or into contact with theanti-triction bearings as shown in Fig. 3.

Alternatively, the collars 7 may first be brought to the necessarypositions upon the spindles and the tool-holding elements then rotateoto cause them to ride towards the abutment collars until a similarcontact is established. The latter method cilitated by driving thespindles, as in the normal operation of the press, and permitting thetips of the bits to come into contact with the er face of the materialto be drilled, in which event the elements (3 will ride upwardly on thespindles until the above dcscribed contact is made either directly withthe collars h or until the anti-friction bear in, s strike the collars.

N 1th either method, as soon as intimate contact is made beti cen theparts, more ment of the tool-holding; elements axially ol' the spindleis immediately and positir arrested whereby to absolutely preventfurthe: riding of the raid elements upon the spindles, and assuring; thetips of the bits; being held in the relative positions desired anddetermined by the adjustments previously made.

lVith constructions such as illustrated, there is substantially notendency tor the abutment collars to turn about the spindles under theinfluence of the power transmitted to the bits and their holdingelements, which explains the positive setting effect and in thecustomary manner well known to those familiar with this art, but due tothe smoothly polished plane surfaces provided on the end contact faces 9and 10, in Fig. 2, the frictional resistance between them issufficiently reduced to substantially elimi- 3 for the results desired,positively to the spindle. The binding effect between the abutmentcollar and the portion of the spindle upon which it is mounted isgreatly enhanced by the provision of the inclined side face 8 of thethread which not only in creases the area of contact between the collarand the spindle but serves to generate an effective radial componentresulting from the axial thrust of the tool-holding element upon thecollar which aids in bringing the interior surface of the collar into amost intimate gripping relation with respect to the exterior surface ofthe spindle.

In the form shown in Fig. 3, the frictional contact between the element6 and the collar 7 is practically totally eliminated due to theinterposition of the anti-friction bearing therebetween. Consequently,substantially no turning moment whatever is transferred by thetool-holding element to the abutment collar, giving full effect to theaxial thrust against the collar in producing the gripping action of thecollar upon the spindle.

It is thus seen that the invention provides a drill chuck which issimple in construction, easy to manipulate, freely accessible, readilyadjustable, and which will positively lock the tool-holding elementsagainst displacement upon their spindles after the necessary preliminaryadjustments have been made.

As required by the patent statutes, the preferred embodiment of theinvention has been illustrated and described. It is obvious, however,that various changes in the details and in the arrangement of theseveral parts can be made without departing from thespirit of theinvention. For instance,

the shapes of the driving spindle and the tool-holding element may bereversed, that is, the terminal of the driving spindle may be in theform of an internally threaded tube while the upper portion of thetoolholding element is in the form of a solid rod exteriorly threaded tocooperate with the internal threads of the spindle, in which event theabutment collar will threadedly ride upon the threaded portion of thetoolholding element, its upper end face serving as its contact facewhich abuts the end face of the spindle. The specially inclined face ofthe thread in this case, as in the previously described forms, facetowards the end contact face of the abutment. It is therefore notintended to limit the inven tion beyond that particularly pointed outand defined by the appended claims.

I claim:

1. In a multipledrill press the combination with a plurality of drivingspindles, of tool-holding elements threadedly connected to the spindles,a limiting abutment adjustable axially of the spindles threadedlymounted in axial alignment with the toolholding elements and provided atone end with a contact face, the side face of the thread engaging thesaid abutment and facing towards the said contact face being inclinedand diverging away from the said contact face.

2. In a multiple drill press the combination with a plurality of drivingspindles, of tool-holding elements threadedly connected to the spindles,a limiting abutment adjustable axially of the spindles threadedlymounted in axial alignment with th toolholding elements and provided atone end with a contact face, the side face of the thread engaging saidabutment and facing towards the said contact face being inclined awayfrom the contact face and having an area greater than the opposite sideface of the threads.

3. In a multiple drill press the combination with a plurality of drivingspindles, of tool-holding elements threadedly connected to the spindles,a limiting abutment adjustable axially of the spindles threadedlymounted in. axial alignment with the toolholding elements, the side faceof the thread engaging the said abutment and facing toward the saidcontact face being inclined away from the contact face and divergingradially from the axis of the spindle at a smaller angle than theopposite side face thereof.

4. In a multiple drill press the combination with a plurality of drivingspindles, of tool-holding elements threadedly connected to the spindles,a limiting abutment adjustable axially of the spindles threadedlymounted in axial alignment with the toolholding elements, thecontact-portions of the said element and abutment being smoothlypolished to form plane surfaces whereby to reduce the tendency of theone to turn in response to turning movement of the other.

In testimony whereof, I sign my name.

LABS H. VOLD.

